Waisman Center investigators study intellectual and developmental disabilities (IDD) through investigating the brain structure and function of individuals exhibiting these conditions or at risk for these conditions, or in animal models of these conditions. The Waisman Brain Imaging Core (BIC) provides all of the tools and services required for these types of investigations and includes facilities for magnetic resonance imaging (MRI), human positron emission tomography (PET), high-resolution PET for animal imaging, ancillary physiological recordings during imaging, and extensive software tools and training for image analysis. This facility occupies a key role in providing systems level neuroscience that lies at the interface between the behavioral and molecular levels of analysis. We propose the following specific aims for the next project period. Aim 1 is to develop and translate hardware and software technologies for magnetic resonance imaging (MRI) neuroimaging studies of normal development, atypical development, and neurodegeneration in both humans and animal models. The objectives of this aim encompass all of the major modalities of MRI and include structural MRI, diffusion weighted imaging to examine white matter connectivity, and functional MRI. We also provide access to a highly realistic MRI simulator to enable participants to acclimate to the procedures and rehearse the behavioral protocols that are used in scanning. Aim 2 is to develop and translate radiotracers and methodologies for using positron emission tomography (PET) neuroimaging to study normal development, atypical development and neurodegeneration in humans. The objectives of this aim include radio- pharmaceutical development to translate the use of novel radiotracers for the study of molecules relevant to understanding IDD. The BIC provides access to expertise in radiotracer development and PET physics expertise to characterize the kinetics and quantification of novel PET neuroligands. The BIC also performs regular maintenance and quality control for the Siemens PET scanner. Aim 3 is to provide high quality macaque and rodent PET neuroimaging services. The objectives of this aim include the maintenance of two microPET scanners and the development of protocols with PIs to use high resolution microPET imaging to characterize the neurochemistry of IDD in non-human primates and rodents. Aim 4 is to provide training and technical support for investigators and their staffs in the use of all of the imaging modalities in the BIC. The objectives of this aim include the conduct of courses and training workshops, regular technical updates at BIC monthly meetings and lab meetings of the participating PIs, specialized consultation with the staff and students of PIs, development of specialized scanning sequences and data acquisition protocols for novel applications and consultation, and support in statistical analysis of imaging data.